Removing something like food dyes is an easy step to
take, but it can have dramatic - and varied - effects. The widely-used
dye, tartrazine, also called FD&C Yellow #5, is a good example, but keep in mind we could list similar "side effects" for any of the petroleum-based colorings. Yellow #5 is not particularly worse than Blue #1, Red #40, etc.

When you eat things with Yellow 5, you lose zinc through your urine and saliva. If you have ADHD, you lose it even faster than someone without ADHD (Ward 1990, 1997). Zinc, an essential trace mineral, is required by hundreds of your body's enzymes involved with the metabolism of protein, carbohydrate, fat and alcohol. Zinc is also critical for wound healing, sense of taste and smell, immune system function, bone strength, thyroid function, blood clotting, cognitive functions, prenatal development, and sperm production. Even a mild deficiency can produce a wide range of physical and mental problems.

All the synthetic dyes are allowed to contain harmful
contaminants like lead, mercury, arsenic, and benzidine (a carcinogen).
Lead usually targets the oxygen-carrying protein in red blood cells first, eventually attacking your nervous system. The primary effects of mercury on infants and children is to damage neurological development. Arsenic can cause several kinds of cancer, as well as headaches and confusion. While it is true that colorings don't have large amounts of any of these contaminants, there is no good reason to consume them.

As long ago as 1985, Pediatrics - the journal of the American Academy of Pediatrics - described the following side effects of Yellow #5: allergies, thyroid tumors, lymphomas (cancer), chromosomal damage, asthma, and urticaria (hives). Even earlier, Cesarani (1978) described the bronchoconstriction of Yellow 5 as similar to aspirin in aspirin-sensitive asthmatics. The connection between this dye and asthma was
the reason the Food and Drug Administration (FDA)
first required it to be listed by name on
ingredient labels.

Shaywitz in 1978 reported that "escape latency in the normal animals [rat pups] fed the food coloring mixture demonstrated
markedly impaired performance in both the T-maze at 20 days of age and the shuttle box at 27
days." He further concluded, "Our results also suggest that hyperactivity should not be the sole factor investigated, and that measures of the effects of food coloring on cognitive function must be carefully evaluated in any future study."
Although this appears to be the only published study comparing the ability of rats or mice to run mazes with and without having been fed food dyes, and Shaywitz' recommendations were ignored, a number of elementary and middle school students have been carying on similar research. See Taylor and his "fuzzy brained mice".

In 1998, Koutsogeorgopoulou described the "clear immunosuppressive effects" of Yellow #5.

Yellow 5
has been shown to damage the ability of nerve cells
to send and receive signals. In order for our brains
to work properly - to think, remember, reason and
learn - the nerve cells must be able to communicate
with each other. In a shocking toxicology study in 2006, Lau showed that a combination of yellow #5 plus aspartame in amounts likely to be found in a single snack, was toxic to developing neurites at a level far beyond that expected from the toxicity of each alone (see d in picture below. Perhaps even more shocking (to the layman) is the assumption by the researchers that that these additives are toxic to developing neurites at any level.

A study in Kuwait reported that children there ate up to 8 times the allowable daily intake (ADI) for a number of colorings, including Yellow #5 (Husain 2006). While how much American children eat today is not known, even the amount of the ADI (7.5 mg/kg body weight) - which is supposed to be safe by definition - has never been tested on children to see how they react to it.

There is an urban legend denied by Snopes.com that drinking Mountain Dew will lower your sperm count. However, considering that one of its ingredients is Yellow #5, which has recently been shown to decrease the sperm count and to increase sperm abnormalities in mice (Mehedi 2009), Snopes may do well to rethink their denial. Indeed, sperm count has declined significantly since the 1940s, and while Mountain Dew may not be as potent as other causes for concern such as pesticides, PCBs or dioxin, at least the Yellow #5 is one for which you can control your exposure.

In 2007, Moutinho showed that rats drinking water with Yellow #5 had a significant increase in the number of white blood cells in the lining of part of their GI tract. An older study on rats showed that Yellow #5 interacts with other foods; not only did it cause growth retardation, but it was actually lethal to the group fed a very low-fiber diet (Ershoff 1977).

Tanaka did a number of studies on various food dyes and mice. One he published in 2005 reports that the Yellow #5 increased physical activity and weight, while a number of behavioural developmental parameters were abnormal. "Nevertheless," he concludes, "the actual dietary intake of tartrazine is presumed to be much lower. It would therefore appear that the levels of actual dietary intake of tartrazine is unlikely to produce any adverse effects in humans." One would think that "presumed" is a strange word to use in a scientific study.

All the food colors tested by Reyes in 1996 (including Yellow #5) inhibited mitochondrial respiration in a dose-related manner. The mitochondria are the tiny energy factories inside the cells of your body. Indeed, in 2003, the FDA issued a warning to hospitals to stop using Blue #1 in tube feeding of patients because the patients were dying with a bright blue colon visible upon autopsy. The FDA admitted that Blue #1 was "a mitochondrial toxin."

As long as we have mentioned Blue #1, we must share with you the good news -- it shows great promise as a medicine. According to an story reported on CNN.com, Blue #1 is known for its ability to counteract the action of ATP. In the case of a severe spinal cord injury, ATP floods the area resulting in increased damage. In a study on rats with spinal cord injuries, those given enough Blue #1 to temporarily turn them blue regained at least some ability to walk.